CODEWITHSUNDEEP
c#
louisetmr
louisetmr

Reputation: 53

after do... while loop Unhandled Exception: System.FormatException: Input string was not in a correct format

So my lab is supposed to ask you how many questions you want and then give you that many randomly generated math problems. At the end it should ask you if you want to have another set of questions or just end and you have the option to answer y or n. when i stop the code there everything works fine but I also need to get the total amount correct printed and when I add that code I get the Unhandled Exception. My problems come from the last three lines before the brackets:

    using System;

class MainClass {
  public static void Main (string[] args) {
    var rnd = new Random();
    string exit = "";
    double score = 0;
    double total = 0; 
    double percent = 0;
    Console.WriteLine("How many problems do you want in a set?");
    double problem = Convert.ToDouble(Console.ReadLine());
    do{
    for(double i = 1; i<=problem; i++){
      double num1 = rnd.Next(1,9);
      double num2 = rnd.Next(1,9);

      Console.Write("Problem {0} : {1}*{2}=? ", i, num1, num2);
      double answer = Convert.ToDouble(Console.ReadLine());

      if(num1*num2 == answer){
        score++;
      }//end if

      total++;
      }
      Console.Write("Another set? <y/n>");
      exit = Console.ReadLine();
      Console.ReadLine();
    }while(exit!="n");
      percent = score/total;
      Console.WriteLine(" {} correct out of {} is a {}%",score,total,percent);
      Console.WriteLine("done");
  }//end main
}//end class

Upvotes: 1

Views: 89

Answers (2)

louisetmr
louisetmr

Reputation: 53

      Console.WriteLine(" {} correct out of {} is a {}%",score,total,percent);

needed 0, 1, and 2

Upvotes: 1

Neil W
Neil W

Reputation: 9162

Either number the parameters {0}, {1}, {2}, or you can now use string interpolation as follows:

Console.WriteLine($"{score} correct out of {total} is a {percent}%");

Upvotes: 1

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